This disclosure is related to the development and the improved manufacturing of micropolarizers (μPol™) (micropol) based on twisted nematic (TN) liquid crystals. VRex, Inc. and Reveo, Inc., the assignee of this application and its parent have several patents and patent applications with regard to the micropol. These prior art documents describe several forms that the micropol may take (including alternating rows, alternating columns and checkerboard configurations), various substances that may be used to make them (polyvinyl alcohol, and various types of liquid crystal), and various methods for fabrication. Many of these methods have shown great promise for manufacturing and are, in fact, presently in use. These patents include U.S. Pat. No. 5,096,520 ('520) issued on Mar. 17, 1992 to Faris; U.S. Pat. No. 5,327,285 ('285) issued on Jul. 5, 1994 to Faris; U.S. Pat. No. 5,537,144 ('144) issued Jul. 16, 1996; U.S. Pat. No. 5,844,717 issued on Dec. 1, 1998; and U.S. Pat. No. 6,384,971 issued on May 7, 2002 to Faris.
Micropol (μPol) panels in which patterned polarizers having alternate lines of perpendicular polarization are used in conjunction with polarizing glasses. In this technique, polyvinyl alcohol (PVA) λ/2 retarder has been the base for building the μPol array. The fundamentals of this μPol rely on the π phase shift induced by PVA. The μPol 100 is built in such a way that it consists of alternately spaced lines with 102 and without 104 the π phase shifter, as schematically shown in FIG. 1.
The advantages of such a μPol include:    Simple processing;    Low cost;    High throughput;
The PVA based μPol, however, has its own shortcomings:    Poor spectral characteristics due to the phase shift mechanism;    Relatively thicker film thickness;    Relatively low spatial resolution;    Difficulty in line width control;    Poor thermal and humidity resistance.
There is room for improvement in developing new fabrication methods that can reduce the cost and the time involved in the manufacturing process itself and in the application of the micropol to flat panel LCD displays or other flat rasterized display devices.
The purpose of this invention is to improve the processes of micropol fabrication and application, particularly for the TN-micropol described in the '871 TN-micropol patent application
This invention describes alternative methods to manufacture a high quality μPol that will essentially eliminate all the above-mentioned problems at a lower cost.